This invention relates to a valve design for use in dispensing product from a pressurized container and more particularly to a valve whose design provides user control over the dispensing rate. This is particularly valuable where pressure in the container is developed from a gas, such as pressurized air or pressurized nitrogen, in which the pressure decreases as product is dispensed.
Applicant's U.S. Pat. No. 5,785,301 and U.S. Pat. No. 6,425,503 and U.S. Pat. No. 6,340,103 are representative of prior art valve designs for use in hand held pressurized containers.
The pressure in most of these barrier containers is maintained as product is dispensed by virtue of having the pressure developed through a hydrocarbon type of gas in which a liquid reserve is contained in the pressured gas chamber. As product is dispensed and the pressured gas chamber increases in volume, the liquid will evaporate to maintain a fairly constant pressure.
It is known to use pressurized gas such as pressurized nitrogen. In those cases, as product is dispensed and the gas pressure chamber increases in volume, the pressure therein drops. This drop in pressure reduces the rate at which product is dispensed and is inconvenient for the user.
Accordingly, pressurized dispensing containers employing pressurized air or nitrogen are not generally used.
However, the use of a hydrocarbon causes environmental concerns. Hundreds of millions of these containers are used. When these containers are disposed, they carry the hydrocarbon with which they are initially charged. Eventually this hydrocarbon is released into the environment.
There is great concern to provide a practical and useable pressurized dispensing container in which the pressure is created by a pressurized nitrogen or pressurized air or some other more environmentally acceptable pressurized gas.
It is a major purpose of this invention to provide a pressurized dispensing container adapted to use pressurized nitrogen or gas that is acceptable to the user.
It is a related purpose of this invention to provide such a container in which the user can maintain a substantially consistent dispensing rate of product throughout the use of the container.
It is a related object of this invention to obtain this consistent dispensing rate in a design which maintains the cost of the valve and the discharge mechanism at a level that will be cost effective for the user.
It is a further purpose of this invention that this ability to maintain a substantially constant discharge rate be easily and readily controllable by the user.
It is another purpose of this invention to provide a valve design which is particularly adapted to be used in a vertical fashion; that is, used through axial movement of the valve element.